package com.srcptit.java.training.kienbd.btvn1;

import java.util.Scanner;

import java.lang.Math;

public class Muc1Bai1SNT {
	public static boolean Songuyento(int n) {// Kiem tra so nguyen to.
            if( n<2 )           return false;
            for(int i=2;i<=Math.sqrt(n);i++)
            if( n%i==0 )       	return false;
            return true;
	}
	public static void main(String args[]){
            Scanner input = new Scanner(System.in);
            String str = input.next();
            int n;
            try {
                 n = Integer.parseInt(str);
                 System.out.println("YES! Thuc hien kiem tra.");
                 if( Songuyento(n)==true ) { 
                     System.out.println(n+" la so nguyen to.");
                 }else {                      
                     System.out.println(n+" ko la so nguyen to.");
                 }
            }catch(Exception e) {
                 System.out.println("NO! Vui long nhap lai.");
            }
            input.close();
	}
} 
